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CX50 JR Owners Manual

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1. REF PART DESCRIPTION 1 ECCJ0001 CYLINDER INCLUDES PISTON RINGS PIN amp CLIPS 2 ZCMUO011 BASE GASKET 0 25mm THICK 2 ZCMUO703 BASE GASKET 0 30mm THICK 2 2 0501 BASE GASKET 0 40mm THICK STANDARD 2 ZCMUO705 BASE GASKET 0 50mm THICK 2 ZCMUO706 BASE GASKET 0 60mm THICK 2 ZCMUO708 BASE GASKET 0 80mm THICK 3 ECMUO060A PISTON KIT A SIZE 3 ECMUO060B PISTON KIT B SIZE 3 ECMUO060C PISTON KIT C SIZE 3 ECMUO060D PISTON KIT D SIZE 4 ZCMOTE11 O RINGS PIPE TO FLANGE 2 REQ D 5 ECMU0155 PISTON RINGS 2 PER SET 6 ECMUSROO SNAP RING FOR PISTON 2 PER SET 7 12 WRIST PIN 8 ECMUO077 BEARING WRIST PIN 9 ZCMUORO7 O RING EXHAUST FLANGE 10 ECMU0086 EXHAUST FLANGE 11 HCBC0612 M6X12 EXHAUST FLANGE SCREW 2 REQ D 12 HCNS0703 7mm NUT TALL 4 REQ D 13 HCWS1401 HARDENED WASHER 4REQ D 14 ECMU0530 CYLINDER HEAD OUTER 15 ZCMUORO2 O RING CYLINDER HEAD LARGE 16 ZCMUV024 O RING CYLINDER HEAD SMALL 17 ZCMUOR10 O RING CYLINDER STUD 4 REQ D 18 ECCS0017 CYLINDER HEAD INSERT 19 ZCMUORO05 O RING CYLINDER HEAD MEDIUM YELLOW 20 ECMU0147 STUD CYLINDER 7mm 4 REQ D ACCESSORY ZKMUOR11 TOP END O RING KIT ACCESSORY ZKCSTE11 TOP END GASKET KIT 23 Parts Exhaust System Exhaust System REF PART DESCRIPTION 1 XCCJ2009 CX50JR EX
2. a nnnnnrnnn na 39 Engine Removal etm 41 Complete Engine Disassembly Procedure 41 Top End Disassembly Procedure eC re ti eter HOCH Cc E HC e Cere e eoe eee 42 Splitting the E 43 Engine Assembly eee 43 Si PE 45 Cl tch Removal eee A Usu een MES dU cH ud 47 Clutch Assembly 49 e le PEE EE 50 SOOT SY SUEY NO p INE 52 Radiator fluid 52 Fuel S AI SySIBITi ro ct sla odo Cd din Le 55 ENEE le ocak a Oud enn cial a aa eka pp M 55 E E 57 57 Wheels amp TS as a a EEA 58 Rear wheel DUNKS A E 58 RT ie 58 me 58 Gall 60 MUS PENSION ntik ta 61 Real SHOCK NE 63 GEERT 64 Ee EEN 64 WEE 67 at FP 69 General Information Specifications General Items CX50 JR Dimensions Wheelbase 35 75 908mm Wheel size 10 254mm Seat height 23 9 607 mm Engine Type 2 stroke single cylinder reed valve Cooling system Liquid cooled Coolant 50 50 antifreeze coolant distilled water
3. REF PART DESCRIPTION 1 0004 RADIATOR WITH 2 MCMUHOO2 RADIATOR HOSE LEFT 3 MCMUCLO7 HOSE CLAMP 4 EACJ0001 MOUNTING BRACKET RADIATOR BOTTOM 5 0608 M6X55mm SOCKET HEAD SCREW 6 0601 M6 LOCK NUT 7 MCKGGROO GROMMET RADIATOR MOUNTING 8 MCCMHOO01 RADIATOR HOSE RIGHT 9 0001 BUMPER RAD BRACKET 10 FCMU0049 OVERFLOW HOSE 20 11 MCMUCLO5 HOSE CLAMP OVERFLOW HOSE 12 ECHA0109 MOUNTING BRACKET RADIATOR TOP 2 REQ D 13 0665 M6X65mm SOCKET HEAD SCREW 14 FCCJ0002 LOUVER SET LEFT AND RIGHT 15 HCCNO0000 5mm CLIP NUT 16 HCBCO0501 M5X12mm SOCKET HEAD CAP SCREW 17 FCMU0022 CAP 1 2 BAR KIT FKMUOOO1 RADIATOR SERVICE REPLACEMENT KIT INCLUDES HARDWARE 18 Parts Electrical System Electrical System REF PART DESCRIPTION 1 0001 COIL W SPARK PLUG CAP 2 ECMUO010C SPARK PLUG AUTOLITE COPPERLITE Autolite 2A ECMUO010I SPARK PLUG AUTOLITE IRIDIUM 3 FCMU0033 KILL SWITCH ASSEMBLY 4 HCBH0502 M5X16mm HEX HEAD SCREW 2 REQ D 5 HCWFO0501 5mm WASHER 2 REQ D 6 HCWP0002 5mm WASHER SPECIAL 2 REQ D 7 HCNL0501 M5 LOCKNUT 2 REQ D 8 ICMUO018 STATOR WITH GROMMET 9 HCBC0535 M5X35mm SOCKET HEAD CAP SCREW 2 REQ D 10 HCBC0525 M5X25mm SOCKET HEAD CAP SCREW 11 HCWFO504 WASHER FOR STATOR 3 REQ D 12 ICMU0036 ROTOR LOW INERTIA 13 ECKG0042 PULLEY WATERPU
4. Parts Carburetor Carburetor REF PART DESCRIPTION 0001 COMPLETE CARBURETOR 14MM 1 RCMUO0305 CARB SLIDE 2 RCMUO601 NEEDLE 3 RCMUOO24 JATOMIZER AU2 62 4 RCMUOOxx MAIN JET xx denotes size 5 RCMUOOxx JET xx denotes size 7 RCMUO301 FLOAT 8 RCMU0102 RUBBER CABLE CAP SEAL 9 RCMUO003 CABLE ADJUSTOR 11 RCMUO006 CARB SCREW 12 RCMUO106 CARB 13 ZCMUOOO7 TOP CARB GASKET 14 RCMUO004 SLIDE SPRING 15 RCMUO0028 NEEDLE RETAINER PLATE 16 RCMUO0007 NEEDLE CLIP 17 RCMUO204 CHOKE ASSEMBLY NOT SHOWN RCMU0209 O RING CHOKE ASSEMBLY 20 RCMUO0009 JFUEL MIXTURE SCREW 21 RCMUO011 JIDLE ADJUSTMENT SCREW 25 RCMU0103 FLOAT BOWL GASKET 26 RCMUO107 FLOAT NEEDLE 27 RCMUO012 DIFFUSER 28 RCMUO0016 FLOAT RETAINER PIN 29 RCMUO0108 JFLOAT BOWL 30 HCWF0401 WASHER 4MM FLAT 31 RCMUO201 FLOAT SCREW NOT SHOWN JRCCM1301 VELOCITY STACK 05 style NOT SHOWN JRCCMO314 14MM CARB RESTRICTOR NOT SHOWN 00026 FUEL LINE 5 NOT SHOWN MCMUCLO4 JHOSE CLAMPS FUEL LINE NOT SHOWN RCMUO022 JCARB VENT HOSE 2 EACH MAIN JET RCMUO055 88 IRCMUOO88 95 RCMUOO95 102 RCMU1102 89 00089 96 RCMUOO6 90 00090 97 RCMUOO7 17 Parts Coolant System ia 15 bog Coolant System
5. uuu 22 Specification 4 TIMING sies ne EE DDR 51 Clutch Jetting 21 HOW aan 55 Clutch Lubricant DOCK MM 4 Replacing EE 10 Troubleshooting 63 Compression test 38 Lubrication Cooling System 52 Recommended 4 Engine Maintenance Specifications 4 Seh d ule rreo as 8 TT EE 57 8 IO 24 Oil Fork Oil Recommended 4 Replacement 12 Optional Components 5 Forks Parts PARES a ba 25 Airbox and Filter 15 Frame cc rrr teri t 28 Bars and Controls 16 69 Bottom End amp Transmission 20 Carburetor 17 Clutch amp Kick Starter 21 Coolant System 18 Engine 20 amp sciet 24 FOI RS 25 el 28 Front Brake 30 Front Wheel 31 Ignition amp Water Pump 22 Ipso ad ad ada nd dolent 15 Plastic A Seat 32 Rear 33 Rea
6. e Engine cutting out on top end e Engine overheating and ultimately seizure e White spark plug CAUTION It is much safer to operate the engine slightly rich as opposed to slightly lean This is because an overly rich engine will just run poorly while an overly lean engine will seize potentially causing an expensive top end rebuild and a DNF To richen the carburetor 1 Change the main jet one number at a time larger 2 Lower the needle clip raising the jet needle one notch at a time until the engine starts to blubber on the top end then move the clip back up one notch or until you get the blubber out FUEL MIXTURE SCREW The smaller brass screw that is towards the front of the engine is a fuel mixture screw This screw will also richen and lean your engine more on the bottom and mid range In warmer conditions turn the screw in In colder conditions turn the screw out Be sure to keep the carburetor very clean and make sure you don t have water or dirt in the carburetor bowl Use automotive carburetor cleaner or WD 40 to clean the carburetor inside and out Cleaning the carburetor Clean the carburetor in a well ventilated area and take care that there is no spark or flame anywhere near the working area this includes any appliance with a pilot light Because of the danger of highly flammable liquids do not use gasoline or low flash point solvent to clean the CABLE MUST carburetor SITJATE DE TNEEN CHOKE EKO 25
7. 11 ft Ib 15 Nm 27 Make sure that the exhaust spacer is on the cylinder 53 in Ib 6 Nm 28 Install the spark plug with a fresh gasket to apply the proper torque to the spark plug when inserting one must first screw the spark plug in until the metal gasket ring causes resistance and then turn another 1 8 to 74 turn Clutch New in 2011 Cobra improved the clutch washer design The new washer stacks have taller springs but are overall shorter and have a single thin shim These new washer stacks are being double sorted at the factory They are first sorted by measured height Secondly each stack with bolt is sorted by measured engagement force Because of this we have been able to widen the range of stack heights that provide an acceptable clutch hit The stacks in each stack of three will measure within 0 05mm 0 002 There are many variables in an automatic centrifugal clutch These variables are set to world class standards from the factory but will change over time as the components wear relax and just plain get used Please see the Tuning Clutch portion of this manual for more helpful info Factors that affect what the clutch spring stack should be include 1 Amount of wear on shoes this is difficult to measure and can only be approximated by the step in the shoe where it rides outside the basket new shoes will not have one old shoes will have a large one 2 Effective length of the shoulder on the
8. 2 Filling your transmission with more than 8 0 oz 235 cc of lubricant will help to transfer heat from the clutch Filling with more than 12 oz 295 cc will degrade performance 3 The oylinder base gasket has been fitted for your engine The code number stamped into the engine cases will guide you to what thickness base gasket is required during a common top end service See the service section of this manual to correspond a code number with a base gasket part number 4 Evaluate the bikes jetting only after it has been warmed up to race temperatures 5 New chains will stretch on first use Never install a new chain prior to a race Always break them in during practice 6 Your Cobra motorcycle has a 10 digit VIN Vehicle Identification Number The first two digits indicate the model and the seventh indicates the model year MY Example CMxxxx7xxx is a 2007 MY CX50 JR 7T Because of the amount of heat generated by the clutch and engine during extended periods of riding it is advisable to remove the ignition cover afterward to allow the ignition to cool off The heat transfers through the cases and can damage the stator as it cools off because of lack of airflow around the stator 10 11 12 If you ever need to weld anything on the bike disconnect the spark plug cap unplug the ignition disconnect the kill switch scrape the paint bare near the area to be welded and put the ground clamp as close to the area to be weld
9. 31 Parts Plastic amp Seat Plastic and Seat PART DESCRIPTION 1 TCHA0107Y FRONT FENDER 1 FRONT FENDER x DENOTES COLOR BLK WHT YEL 1A FENDER BOLT M6X16mm FLANGE HEAD 4 REQ D 2 NUMBER PLATE FRONT 2 FRONT PLATE x DENOTES COLOR BLK WHT YEL 2A M6X16mm FLANGE HEAD BOLT FRONT NUMBER PLATE MOUNT 3 amp 4 RADIATOR SHROUD SET LEFT amp RIGHT YELLOW 3 amp 4 RADIATOR SHROUD SET x DENOTES COLOR BLK WHT YEL 3A RADIATOR PAD 5 FUEL TANK NO CAP OR PETCOCK 5A M6X20mm PHILIPS HEAD SCREW SEAT 8 SHROUD HOLD 5B SPACER SEAT amp SHROUD HOLD 5C SPACER FRONT TANK MOUNT 2 REQ D 5D M6X85mm SHCS FRONT TANK MOUNT 5E M6 LOCK NUT FRONT TANK MOUNT BOLT 5F M6X45mm SOCKET HEAD CAP SCREW 5G BUSHING REAR TANK MOUNTING CAP FUEL TANK HOSE FUEL CAP FUEL PETCOCK SEAT 9A SEAT COVER REPLACEMENT M6X40mm SHCS SEAT HOLDING 9C STRAP HANDLE 10 amp 11 NUMBER PLATE SET LEFT AND RIGHT WHITE 10 amp 11 NUMBER PLATE SET x DENOTES COLOR BLK WHT YEL 10A M6X16mm FLANGE HEAD BOLT FRONT SECURE 10B M6X20mm FLANGE HEAD BOLT FENDER amp REAR SECURE 10C M6 NYLOC FLANGE NUT 10D M6X16mm FLANGE HEAD BOLT FRONT SECURE 10E M6X20mm FLANGE HEAD BOLT FENDER amp REAR SECURE 10F HCNF0602 M6 NYLOC FLANGE NUT 12 TCHA0112WHT FENDER REAR 12 FENDER REAR DENOTES COLOR BLK WHT YEL 12A M6X16mm FLANGE HEAD BOLT FENDER amp AIRBOX ACCESSORY GRAPHIC KIT ACCESSORY BODYWORK KIT JR
10. 37 CAUTION Do not use a jaw type puller or use the 6mm tapped holes as jackscrews or you are likely damage the clutch or drum 4 f necessary apply heat to the center clutch hub CAUTION Do not heat the crankshaft threads or the aluminum shoes 5 Keep tension on the puller as you are heating it A WARNING The clutch will often pop off under tension from the puller and it will be verv hot CLUTCH WASHER STACKUPS Once the clutch is removed and cool to touch carefully put it into a vice and remove the center shoulder bolt out of each clutch shoe Vou mav have to heat the center hub again to remove the bolts Once you get a bolt loosened carefully remove it with the shoe and observe the way the spring washers are stacked Clean the washers and bolt if you intend to reuse The spring stacks in your Cobra clutch will contain 11 individual springs and flat washer s configured as a 5 75 stack See figure 38 This clutch is designed such that it reconfigured by the customer to achieve different clutch engagements hits by changing washer counts and configurations CAUTION Generally reassemble the springs as you removed them from the engine or as you received them from Cobra If you are unsure call the Cobra Technical Support Group 517 437 9100 and consult the experts 47 CLUTCH ASSEMBLY REFERENCE DRAWING PART DESCRIPTION CAMUOO013 Set of three shoes springs bolts flat washers amp nuts 2
11. BLACK ACCESSORY BODYWORK KIT JR WHITE ACCESSORY 0002 BODYWORK KIT JR YELLOW 32 Parts Rear Brake Rear Brake System REF PART DESCRIPTION 1 BAKGO0002 BRAKE SYSTEM REAR M C LINE CALIPER 2 BCDC0009 BRAKE PIVOT BOLT 3 00501 SEAL BRAKE PEDAL 2 REQ D 4 00099 BRAKE PEDAL 5 BCMUSPO2 BRAKE RETURN SPRING 6 HCBC0601 M6X16mm SOCKET HEAD CAP SCREWS 7 FCEX0018 BRAKE ADJUST ECCENTRIC 8 0003 PUSH REAR BRAKE 9 BCKGO0006 WHEEL SPACER FLOATING CARRIER 10 0103 BRAKE CARRIER WITH PAD 11 HCBF0635 M6X35mm FLANGE HEAD BOLT 12 HCBF0620 M6X20mm FLANGE HEAD BOLT 13A 0000 BRAKE HOSE CLAMP 2 REQ D for hose with clear cover 13B 0006 BRAKE HOSE CLAMP 2 REQ D for hose with black cover 14 HCPP0832 BRAKE HOSE CLAMP FASTENER 2 REQ D 15 BCMU0502 BRAKE ROTOR 16 0601 M6X16mm SOCKET HEAD CAP SCREWS 5 REQ D 17 HCBFO620 M6X20mm FLANGE HEAD BOLT 2 REQ D 18 0012 BRAKE MASTER CYLINDER 19 0010 REPLACEMENT BRAKE HOSE 20 0013 CALIPER REAR BRAKE 21 BCMU0022 BRAKE RUBBER CAP ACCESSORY BKKG0001 BRAKE PADS WITH E CLIP ACCESSORY BCKGO031 BLEED KIT MULTIPLE SYRINGES FITTINGS amp HOSE ACCESSORY BCKGOO14 FITTING KIT ACCESSORY 50015 MASTER CYLINDER PISTON SEAL KIT ACCESSORY BCKGO016 RESERVOIR SEAL K
12. CAMUOO010 Set Of three springs washers bolts amp nuts PAIRS DA WASHERS s we E SUE TURNED k CR DISH BTACKED A D D IF MORE THAN GRE FLAT WASHER Sl MA Figure 38 Some configuration of clutch spring stack Each spring stack contains multiple springs Belleville washers arranged into three four or five flying saucers or turned away against the flat washer s Shown is the 4 gt stack Stack Total Flying Saucers Turned Away Std Flat Springs or Cymbal Pairs or Dish Stacked Washer s 57 li 5 1 VARIED Clutch adjustment washers Vour Cobra comes stock with flat washer s at the bottom of the spring washer stack Cobra offers several thicknesses of thin adjustment washers that allow clutch engagement tuning Increasing the flat washer s thickness increases the engine speed for clutch engagement thus increasing the abruptness of clutch engagement harder hit Converselv decreasing the flat washer s thickness decreases the engine speed for clutch engagement thus decreasing the abruptness of clutch engagement softer hit Part f Thickness mm inch 5 015 1 5 0 060 5 012 1 2 0 047 5 008 0 8 0 031 5 006 0 6 0 025 5 005 0 5 0 020 5 004 0 4 0 015 5 003 0 25 0 010 5 001 0 12 0 005 0022
13. CLUTCH SHIM KIT Use the table above to order adjustment washers Replace the stock washer with the proper combination of adjustment washers that delivers the desired clutch hit CAUTION 48 It is easy to prematurely damage the clutch and other engine components with improper clutch adjustment If you are unsure of how to adjust the clutch contact the Cobra Technical Support Group before making adjustments Clutch shoe wear Ifthe clutch has been slipping and shows signs of glazing it is best to replace the shoes We have found that once the shoes are glazed even if deglazed with emery paper or a file the performance is reduced e The best way to prevent glazing is by not gearing too high changing the oil as specified and by not blipping the throttle Every time you blip the throttle you are working your clutch springs Clutch basket wear e The internal diameter of a new clutch basket should measure 7 84 10mm Over time the clutch shoes will wear the internal surface down creating a bigger ID and causing a later engagement The maximum ID we recommend to allow is 84 25mm CAUTION The clutch produces a tremendous amount of heat and when a rider is blipping the throttle This makes the clutch and clutch springs wear out quicker This also makes your engine tend to run hotter which decreases engine power lt is important to train your rider NOT to be a throttle blipper CAUTION Sludge build up between the spring
14. SPROCKET 15 T 24 HCBHO805 M8X12mm SCREW COOLANT DRAIN 25 HCWCO0000 COPPER GASKET 26 ECMU0233 FITTING CRANKCASE VENT LARGE 27 ECMU0577 VENT HOSE CRANKCASE 20 Parts Engine Clutch and Kicker i l PES ei d Y y Es fi 4 r ps ki d i E E k E d O UI d es i 2 e Sei Se fi w B SE I E Qr i 2 T 2 i A D s al Engine Clutch and Kick Starter REF PART f DESCRIPTION 1 CAMU0005 CLUTCH COMPLETE 2 CAMUO013 CLUTCH SHOES SET OF 3 WITH BOLT amp WASHERS 3 CCMU0029 CLUTCH ARBOR 4 CAMUO010 SPRINGS WASHERS amp BOLTS SET OF 3 5 HCBS0004 CLUTCH BOLT 3 REQ D 6 ECMUO018 CLUTCH NUT SPECIAL 7 ECMUO120 CLUTCH BASKET WITH NEEDLE BEARING 8 ECMU0119 CLUTCH BEARING 9 ECMUO040 CLUTCH TO HUB SPACER 0 030 0 76mm 2 REQ D 9A ECMUOO40T CLUTCH TO HUB SPACER THIN 0 015 0 38mm 10 ECMU0132 COOLANT FITTING KIT EKMU0013 COMPLETE GEAR CFD UPGRADE KIT KIT EKMU0033 CFD REFRESH KIT W NUT SPRING AND FRICTIONS 11 ECMU0306 SLIP HUB V3 CFD 12 ECMU0249 FRICTION MATERIAL V3 CFD THICK 2 REQ D 13 ECMU0305 BUSHING V3 CFD 7mm 14 ECMU0301 GEAR V3 CFD 15 ECMU0308 BELLEVILLE SPRING V3 CFD 16 ECMU0307 NUT V3 CFD 17 HCCP0002 COTTER PIN 3 32 X 1 1 2 18 EAMUO001 KICKSTART GEAR amp SHAFT 19 ECMUO 1 16 S
15. clutch arbor bolt see Figure C1 Nominal is 16 00mm 0 630 As this decreases the spring stack needs to decrease equally This can change due to the shoulder bolt setting into the arbor see C2 Figure C1 45 spring stack accordingly i e if your effective shoulder length is 0 5mm short of the 16 00 19 w If your effective shoulder length is off or your shoes Sink Mark are worn adjust the height of your overall combined gt measurement decrease the overall combined spring stack height by 0 5mm or if your shoes are worn by 0 5 mm increase the overall combined spring stack height by 0 5mm Figure C1 Frequently asked questions Q When should the springs be replaced A When the clutch hit occurs too early or too late Q Should the clutch springs be replaced if the shoes wiggle on the arbor A Not if the clutch is hitting correctly Don t mess with it Q What is the acceptable tolerance on any of the measurements A For the most part that does not matter Suffice it to say that any efforts to make the three shoes behave identically will make the best performing clutch Taking extra time to balance the three stacks shims springs bolts etc to as close to the same length as you are willing to put effort into will result in a better performing motorcycle Q One of my two riders weighs 85 pounds and the other weighs 45 pounds Should have their clutches adjusted differently because o
16. manual for more information on proper clutch care Gearing For a bike with a centrifugal clutch it s better to be geared too low than too high What happens with improper gearing Poor performance Not enough top end speed No snap Over heat clutch Premature failure of engine seals bearings amp electronics High clutch wear Mud y y NG 9 AT Throttle Blipper novice It may be helpful to set up the clutch to hit early for smooth power delivery 60 Suspension Adjustment 1 Front forks 1 1 Fork oil 1 1 1 Oil type 1 1 1 1 Heavier weight oil more damping slower responding 1 1 1 2 Lighter weight oil less damping quicker responding 1 1 2 Oil quantity level 1 1 2 1 Greater quantity higher level greater bottoming resistance stiffer near the end of the travel 1 1 2 2 Smaller quantity lower level less bottoming resistance less stiff near the end of the travel 1 2 Fork spring optional spring 1 2 1 Stiffer spring higher spring rate stiffer throughout the travel 1 2 2 Less stiff spring lower spring rate less stiff throughout the travel 1 3 Fork height 1 3 1 Rise in clamps for quicker turning 1 3 2 Lower in clamps for improved straight line stability 2 Rear shock 2 1 Shock spring optional spring 2 1 1 Stiffer spring stiffer throughout the travel 2 1 2 Less stiff spring less stiff
17. mm wrench 8 10 14 17 amp 19 mm sockets 3 4 amp 5 mm Allen wrench 7 mm nut driver flat or Phillip screwdriver for hose clamps Spring remover Flywheel clutch puller MCMUTL68 Clutch nut removal tool Call local dealer for details Procedure 1 Remove the seat 2 Turn of the fuel at the petcock and disconnect the fuel line 3 Remove the tank 8 mm socket 4 Remove the carburetor from the inlet flat head or Phillips head screwdriver 7 mm nut driver Remove the silencer amp pipe spring remover 8mm socket Locate a suitable container for the engine coolant and disconnect the coolant lines connected to the engine 8 mm socket NOTE If the coolant looks to be free of contaminates it may be reused 7 Remove the master link from the chain 8 Remove front engine mount bolt 13 mm socket 6 mm hex key 9 Remove the swingarm bolt 19mm socket NOTE Only drive the swingarm bolt far enough to clear the engine leave it holding the one side of the swingarm to the frame 10 Remove the engine from the right side of the frame Complete Engine Disassembly Procedure 1 Remove the magneto cover 4mm Allen 2 Remove the bolt from the water pump shaft 4mm Allen and slide off the belt cover and the water pump belt 3 Using a flywheel holding tool and 14mm socket remove the nut that secures the flywheel 4 Using the Cobra flywheel clutch puller HMCMUTL68 remove the flywheel from the cranks
18. reading possible e Because of the geometry of the spark plug used in this Cobra Motorcycle the adapter used with your compression tester must have a similar volume protruding into the combustion chamber to establish an accurate value e Length of hose on the compression tester will affect the reading The shorter the hose length the more accurate your reading will be Because of these difficulties in measuring an absolute compression value a useful relative value can be achieved by testing your bike s compression with your own particular gauge after a new top end or when the bike is new so that you know what your particular gauge reads on a fresh engine When it has dropped to 90 of its original value the engine will be down on power and would benefit from a rebuild When it s dropped to 80 it really needs rebuilt Using the table below will help you determine monitor the condition of your top end Engine is Fresh Engine Down on Power Engine NEEDS Rebuilt Measured Value Measured Value 0 9 Measured Value 0 8 Example 110 psi 110 psi 0 9 99 psi 110 psi 0 8 88 psi Your Values Procedure for Compression Testing 1 Shut off the fuel petcock 2 Install the compression gauge into the spark plug hole 38 3 Hold the throttle wide open and kick repeatedly approximately 20 times or until the gauge reading does not increase in value with each kick Base Gasket Selection Tools required e 17
19. to a motorcycle Any kinks dents or damage done to the pipe will result in a major performance loss NOTE sure to take the pipe off and any carbon that may be built up Carbon build up is created from exhaust Exhaust has oils in it and the oils cling to the walls of the inside of the pipe Over a long period of time the diameter of the pipe will decrease due to carbon build up So it is essential to clear the residue CAUTION It is important to repack the silencer Signs of your silencer needing to be repacked are The bike is louder than normal 1055 of power 57 Wheels amp Tires Rear wheel pullers Disassembly 1 Remove axle and back wheel assembly 2 Pull the rear wheel pullers out of the back of the swing arm Figure 47 Rear wheel alignment Either e Accurately measure the distance from the swingarm pivot to the axle center on each side or e From the rear of the bike sight up through both sprockets to ensure that the chain is running in a straight line no bend in between or jog at either sprocket Tuning Clutch There are performance characteristics to observe and things to measure 1 Performance characteristics to observe a Clutch coming in too late i Engine rev s to a high RPM before moving the motorcycle ii Clutch never fully engages on a reasonable straight stretch iii Basket turns blue in short amount of time Clutch coming in too early i Motorcycle moves too soo
20. water pump and the device is not orientated correctly If the tool does not sit flat against the cases the orientation of the tool to the engine is not correct Make sure that the top alignment pin is in the 274 unthreaded hole the bottom alignment pin is also in the 274 unthreaded hole and that the relief for the stator bolt head is oriented toward the stator 10 Hold the installation tool firmly against the engine case and tap on the end of the water pump shaft with a dead blow hammer until the insertion punch is needed 11 Continue driving the assembly with the punch until the head is flush NOTE The insertion punch is 0 010 0 25mm longer than the housing so as to seat the water pump assembly just in from the case surface 12 The assembly is installed properly when the retaining screw can be tightened and it does not cause a bind on the spinning shaft use medium strength thread lock on the retainer screw NOTE It may be necessary to tap the water pump shaft in hammer and out with slide hammer to insure proper free operation of the shaft 54 13 Reinstall the pulley belt and fan cover using a 3mm hex key to stop the rotation of the water pump assembly while tightening with medium strength thread lock to 10 ft lb 14Nm 14 Reinstall the cover NOTE Refill the coolant system with 50 50 antifreeze coolant distilled water CAUTION Do not mix Propylene Glycol based coolant antifreeze solutions with Ethylen
21. 0 MOWAT KA SCAR AS CHOKE KOE 1 Make sure the fuel is shut off and remove the carburetor Remove the carburetor Drain the fuel from the carburetor Disassemble the carburetor Immerse all the metal parts in a carburetor cleaning solution ELBOW After the parts are cleaned dry them with compressed air 7 Blow out the fuel passages with compressed air 8 Assemble the carburetor Figure 45 Proper carburetor top 9 Install the carburetor onto the motorcycle installation And location of rectangular slide indexing pin and vent elbows CHENS an Mi po 9 CAUTION The motorcycle will only operate properly if the carburetor top is installed properly with the mounting screws cable and choke knob oriented as shown in figure 45 56 Reeds The reeds must lav flat on the reed cage If the reed tips aren t lying flat replace them immediately The reeds must have a tight seal on the reed cage If the reed is damaged in any way replace it This means cracks chips and ruptures Anything abnormal replace the reeds Take the reed cage out and hold it up to the light and look in through the cage If you see light between the reed pedals and the frame then replace the reeds If you do not see light then the reeds should be ok See figure 46 mw TEN Figure 46 The presence of light indicates that the reeds should be replaced or possibly turned Over Exhaust The pipe is a crucial element
22. 0 x 1 25 Clutch bolts 12 144 16 M6 x 1 0 Engine mount bolts 22 265 30 M8 X 1 25 Swingarm pivot 21 250 28 M14 X 2 0 Shock bolt 35 420 47 M10 x 1 5 Triple clamp top 12 144 16 M8 x 1 25 Triple clamp bottom 6 72 8 M6 x 1 0 Water pump impeller 3 6 44 5 M5 x 0 8 Intake manifold bolts 4 6 55 6 2 M6 X 1 0 Ignition rotor nut 33 400 45 M10 x 1 25 Rear sprocket bolts 18 216 24 M7 X 1 0 Axle nuts 25 300 34 M12 X 1 25 Apply high strength thread locking agent when installing Apply medium strength thread locking agent when installing SP To apply the proper torque to the spark plug when inserting first screw the spark plug in until the metal gasket ring causes resistance and then turn another 1 4 turn Optional Components Call your dealer or the factory for details e Carburetor jets e Sprockets Suspension Springs Weight of Rider Ib Fork Spring Shock Spring Less than 38 light r 15 Nimm SCMUOH04 275 Ib in red i KCCJ0021 SCMUOHOB 285 Ib in SE 21 Ib in 3 70 N mm yellow KCCJ0025 SCMUOH06 295 Ib in 46 to 55 stiff 25 Ib in 4 40 N mm white Tall Seat Not AMA Legal Bar Risers Wide Foot pegs Break In Procedure Your Cobra CX50 JR is a close tolerance high performance machine and break in time is very important for maximum life and performance The CX50 JR can be ridden hard after the first hour break in time Cobra recommends Bel Rav H1
23. A NOTE provides key information to make procedures easier or clearer MCCJ2013 0 Table of Contents General Information i iii aa tat bata is 4 Sp cifications General 4 Specifications Torque 4 Optional Center geseit oii quie oie cele ceto qid e qute eie cute do zio Cat ntn Gun 06060446 atn qn 5 Break In Procedure 5 Starting Procedure o op pi o e b 6 Uu er 8 ae dado 8 ele EE 9 Replacing Transmission Clutch Lubricant 10 Proper Chain adjustment l niei 11 Air Filter Cleaning EE AERE EAR 11 Fork Oil Replacement ENEE NEEN Eu 12 Cobra Frictional Drive V3 ret Gee Genes 13 curet t PETRI 15 Parts Airbox and Inlet System 15 Parts Bars and Controls 16 Parts s Carburetor si e i e tente tH e n e Ete ne tt eua 17 Paris Goolant Systeri tete SZ 18 Parts Electrical System 19 P
24. BOTTOM SLIDER 11 M6X40mm FLAT HEAD BOLT 2 REQ D 12 M6 LOCKNUT 2 REQ D 13 WHEEL PULL ASSEMBLY BLOCK CAP BOLT AND WASHER 14 WHEEL PULL 15 WHEEL PULL ENDCAP 16 8mm FLAT WASHER 17 M8X65mm HEX HEAD BOLT FULL THREAD 18 SWINGARM PIVOT BOLT 195mm 19 M12 LOCK NUT 20 AXLE BOLT 195mm 22 AXLE WASHER 23 M12 LOCK NUT 24 M10X40mm FLANGE HEAD BOLT 25A BRAKE HOSE CLAMP 2 REQ D for hose with clear cover 25B BRAKE HOSE CLAMP 2 REQ D for hose with black cover HCPP0832 BRAKE HOSE CLAMP FASTENER 2 REQ D 37 Service Trained technicians with precision gauging and proper assembly fixtures carefully assemble all Cobra engines to specific tolerances If you feel you have the skills and the appropriate tools to perform the following service tasks please follow the instructions closely The part numbers are listed throughout to help you when ordering parts from your local Cobra dealer If you do not feel comfortable with the service work log on to www cobramotorcycle com to find a cobra dealer or call 517 437 9100 Engine Service One method for determining whether the top end of your engine needs rebuilt is to perform a wide open throttle kicking compression test Before performing the procedure please read the caution notes below CAUTION e There is a large wide range of variability in reading compression gauges e The head volume of this Cobra Motorcycle is very small and requires 20 kicks before you establish the most accurate
25. CAUTION For any seals that are to be installed apply a light amount of grease to the seals ID assembly lube on all bearings and a small amount of Loctite to the OD 1 Press the three bearings into the respective holes in each case half 2 Press in the crank seals such that the concave side faces the crank weights 3 Press in the counter shaft seal concave side faces inside of transmission 4 Install the water pump assembly wire ring retainer 5 Press in the water pump assembly 6 Tap both ways axially then verify easy rotation 7T Inspect the crankshaft for proper true geometry no more than 0 002 0 05mm measured at bearing journal area while supported from the ends CAUTION Insert a 7 05mm 0 278 shim between the crank throws before pressing on the crank 8 Insert the case screws with the proper lengths at locations shown 9 Torque to 12 Nm 105 in Ib in the pattern shown in figure 32 10 Trim away any excess gasket material if necessary Figure 32 NOTE Check engine mount holes for excess material that may cause problems in engine installation 11 Install the piston with new wrist pin bearing and pin and clips CAUTION Be sure to install the piston such that the arrow on the top piston surface points to the exhaust front of bike engine and put assembly lube on the connecting rod bearing 12 Install the piston rings CAUTION Ring end gap should be no less than 0 25 mm 0 010 and no mo
26. DISCLAIMER OF WARRANTY This motorcycle is sold as is with all faults obvious or not There are no warranties expressed or implied including any warranty of merchantability and warranty of fitness for any particular purpose WARNING THE COBRA CX50JR IS A COMPETITION MODEL ONLY AND IS NOT MANUFACTURED FOR NOR SHOULD IT BE USED ON PUBLIC STREETS ROADS OR HIGHWAYS THE USE OF THIS BIKE SHOULD BE LIMITED TO PARTICIPATION IN SANCTIONED COMPETITION EVENTS UPON A CLOSED COURSE BY A SUFFICIENTLY SKILLED RIDER AND SHOULD NOT BE USED FOR GENERAL OFF ROAD RECREATIONAL RIDING IMPROPER USE OF THIS MOTORCYCLE CAN CAUSE INJURY OR DEATH THIS BIKE IS INTENDED FOR EXPERIENCED RACERS ONLY AND NOT FOR BEGINNERS IT IS YOUR RESPONSIBILITY AS THE OWNER OF THIS COBRA MOTORCYCLE OR AS THE PARENT OR LEGAL GUARDIAN OF THE OPERATOR TO KEEP THIS COBRA MOTORCYCLE IN PROPER OPERATING CONDITION THIS BIKE WAS DESIGNED FOR RIDERS THAT WEIGH LESS THAN 80 LBS WITH FULL RIDING GEAR AND SHOULD NOT BE OPERATED BY RIDERS THAT WEIGH MORE BE SURE THAT THE RIDER ALWAYS WEARS ADEQUATE SAFETY GEAR EVERYTIME HE OR SHE RIDES THEIR COBRA MOTORCYCLE IMPORTANT SAFETY NOTICE Failure to follow WARNING instructions could result in severe injury or death to the machine operator a bystander or a person inspecting or repairing the machine CAUTION A CAUTION indicates special precautions that must be taken to avoid damage to the machine NOTE
27. Displacement 49 8 cc Bore and stroke Ignition system Spark plug Gap Ignition timing Fuel type Premix Oil type Premix oil ratio after break in Carburetion Slow Pilot Jet Main Jet 39 mm x 41 7 mm Electronic analogic advance e Autolite XS61 amp 4261 Autolite 0 023 0 025 0 58 0 64 mm 0 035 0 9 mm Before Top Dead Center BTDC High octane pump gasoline Bel Ray H1 R 40 1 to 50 1 14 mm Dell Orto 55 92 Float Height 16mm 0 5mm 0 63 0 020 Transmission Speed Clutch Single Cobra 3 shoe Final drive ratio 13 37T or 14 38 T Chain 420 Transmission clutch oil type Cobra Venom 3 Shoe Clutch Milk Quantity 235 350 ml 8 120z Chassis Front tire 2 50 10 Pressure 15 psi minimum Rear tire 2 75 10 Pressure 15 psi min 20 psi for hard pack or rocky conditions Front fork Cobra 30mm USD Fork oil type SAE 2 5 weight Fork oil Left brake side Fork oil Right side Rear Shock 120 ml 4 00z 60 ml 2 00z Compression Low 7 High 7 No Rebound Adj Specifications Torque Values Fastener value Nm Size amp Remarks Cylinder head nuts 10 3 123 14 M7 X 1 0 Crankcase bolts 8 8 105 12 M6 x 1 0 Spark plug SP SP SP M14 x 1 25 Stator bolts 2 1 25 2 8 M5 X 0 8 Stator cover bolts 1 7 20 2 3 M4 X 0 75 Clutch cover bolts 5 8 70 7 9 M6 X 1 0 Clutch nut 40 480 54 1
28. ET SCREW M6 1 0 SCMU0056 SHOCK SLEEVE BLACK SCMUO100 BUMPER TAPPERED SHOCK SCMU0040 SHOCK SPRING PAD SCMU0054 SHOCK SPRING PERCH SCMUOHO05 SPRING STANDARD 285 lb in ISCMUOHO4 SPRING LIGHT 275 Ib in SCMUOHO6 SPRING HEAVY 295 Ib in A 5 55 1040 M10X40 FLANGE HEAD BOLT 35 Parts Shock Inside Rear Shock REF PART DESCRIPTION 1 SCMU0037 O RING LOW SPEED COMP ADJUSTER 2 SCMU0038 HIGH SPEED COMP ADJUSTER 3 SCMUO036 JO RING COMP ADJUSTER 4 SCC60007 JO RING COMPRESSION ADJUSTER 5 SCMUO051 O RING IFP 6 SCMUO052 FP SEAL BAND 7 SCMUO033 O RING SHOCK BASE 8 SCMU0050 RESERVOIR CAP RETAINER RING 9 SCMUO035 JO RING CHARGE CAP 10 HCBBO506 5 X 6mm LONG BUTTON HEAD STAINLESS STEEL 11 SCMU0044 HEAD BUMPER 12 SCMU0048 SHAFT BUSHING 13 ISCMUOO46 KRING SEAL 14 6 00034 SEAL HEAD 15 SCMUO047 SPACER X RING 16 SCMUOO45 DUST SEAL 17 SCC60014 PISTON BAND 36 Parts Swingarm Assembly PART DESCRIPTION GACJ2011 SWINGARM GCMUO001 SWINGARM BUSHING SINGLE PIECE 4 REQ D SPACER PIVOT TUBE 2REQ D CHAIN GUARD M5X12mm FLAT HEAD SCREW 5mm FLAT WASHER M5 LOCK NUT M6X20mm FLANGE HEAD BOLT 2 REQ D CHAIN GUIDE ASSEMBLY COMPLETE 10 CHAIN GUIDE
29. HAUST PIPE 2 ZCMOTE11 HEADER PIPE O RINGS 2 REQ D 3 00005 EXHAUST SPRING SHORT 4 MCMUGRO2 GROMMET KIT 5 XCMU0028 PIPE SILENCER SEAL 6 XCMU0032 SILENCER 7 MCMUGRO3 MOUNTING GROMMET 2 REQ D 8 0001 5 2 9 HCWF1478 SILENCER GROMMET WASHER 2 REQ D 10 HCBFO625 M6X25mm FLANGE HEAD BOLT 2 REQ D ACCESSORY XCMU0026 SILENCER PACKING KIT 24 Parts Forks amp Triple Clamps Front Forks and Triple Clamps REF PART DESCRIPTION 1 0001 FORK ASSEMBLY FORK LEGS ONLY 2 00011 FORK GUARD SET 3 TCC60019 WASHER FORK GUARD 4 REQ D 4 0601 M X16mm SOCKET HEAD CAP SCREW 4 5 BCC60015 BRAKELINE CLAMP 6 HCBC0612 M X12mm SOCKET HEAD CAP SCREW 2 REQ D 7 HCNLO601 M6 LOCKNUT 2 REQ D 8 FACJO003 TRIPLE CLAMP BOTTOM ASSY JR CLAMP amp STEERING STEM 9 FCCJ0019 TRIPLE CLAMP TOP JR 10 HCNJO102 JAM NUT STEERING STEM 11 0806 M8X30mm SOCKET HEAD CAP SCREW 4 REQ D 12 HCBC0820 M8X20mm SOCKET HEAD CAP SCREW 4 REQ D 13 00404 HANDLE BAR CLAMP KIT SHORT STANDARD 13A 00403 HANDLE BAR CLAMP KIT TALL 14 FCMU1103 DUST COVER 2 REQ D 15 SCMUO036 O RING 2 REQ D 16 FCMUO023 SPACER 2 REQ D 17 00024 SEAL 2 REQ D 18 00004 STEERING HEAD BEARING 2 REQ D 19 HCBC0625 M6X25mm SOCKET HEAD CAP SCRE
30. IT ACCESSORY 50017 CALIPER BOLT O RING KIT ACCESSORY BCKGO018 CALIPER PISTON SEAL KIT ACCESSORY 50019 PAD RETURN SPRING 4 LEG SPRING ACCESSORY ZCMUOROS9 O RING BANJO FITTING 33 Parts Rear Wheel Rear Wheel REF PART DESCRIPTION 1 WAKG2007R REAR WHEEL W BEARINGS 2 WCMU1075D TIRE REAR 10X2 75 DUNLOP MX51 3 WCMUTU10 TUBE 10 4 PCMUO001 MASTER LINK 420 5 PCMUO0100 CHAIN 420 X 100 6 PCMU0138 38T SPROCKET STANDARD 6A PCMUO1xx SPROCKET xx DENOTES TEETH RANGE OF TEETH 34 45 7 HCBHO702 M7X30mm HEX HEAD BOLT 4 REQ D 7A HCWFO0701 7mm FLAT WASHER 4 REQ D 7B HCNLO701 M7 LOCKNUT 4 REQ D 8 WCMUO016 REAR AXLE 10 WCMUO101 WHEEL SPACER 11 WCMUO120 WHEEL BEARING SPROCKET SIDE 12 WCMU0034 WHEEL BEARING SPACER 13 WCMUO020 WHEEL BEARING BRAKE SIDE 14 BCMU0502 BRAKE ROTOR 15 HCBC1616 M6X16mm SOCKET HEAD CAP SCREWS 5 REQ D 16 BCKG0103 BRAKE CARRIER 17 0006 WHEEL SPACER FLOATING CARRIER 18 HCWF1202 AXLE WASHER 19 HCNL 1201 AXLE NUT 12MM ACCESSORY 0104 BRAKE CARRIER PAD 34 Parts Shock Rear Shock PART DESCRIPTION SACJ2012 SHOCK ABSORBER SCMU0043 SHOCK BEARING SPERICAL SHOCK MOUNT 2REQ D SCMUO0039 O RING SHOCK BUSHING 4 REQ D SCMU0042 SHOCK MOUNT BUSHING 4 REQ D SCMU0058 SHOCK WHITE NYLON TIP S
31. KGHOOA HOSE CLAMP CARBURETOR TO MANIFOLD 7 RACMO002 CARBURETOR 14mm 8 RCCM1301 VELOCITY STACK 9 MCKGHO01 HOSE CLAMP AIR BOOT TO CARBURETOR 10 RCMU0403 AIR FILTER WITH BOOT 11 RCMUOA405 AIR BOX JR 12 TCCJ0004 MUD FLAP 13 HCBB0612 M6X12mm BUTTON HEAD BOLT 2 REQ D 14 RCMU1407 BRACKET MUD FLAP 15 ECCS0030 REEDS REPLACEMENT KIT 16 FCMU0026 FUEL LINE 5 NOT SHOWN 17 MCMUCLO4 HOSE CLAMPS FUEL LINE NOT SHOWN 18 RCMUO0022 VENT HOSE NOT SHOWN 15 Parts Bars and Controls Bars and Controls REF PART DESCRIPTION TCMUO0019 HANDLEBAR ALUMINUM TCMUO008 GRIPS SET OF TWO SCOTT WAFFLE FCMUOO66 THROTTLE ASSEMBLY FCPW0004 CABLE COVER FCMU0021 THROTTLE COVER FCMU0019 THROTTLE CABLE BAKG0003 BRAKE ASSEMBLY FRONT FCMUO033 KILL SWITCH ASSEMBLY ool o On HCBC0803 M8X30mm SOCKET HEAD CAP SCREW 4 REQ D HCBC0825 M8X25mm SOCKET HEAD CAP SCREW 4 REQ D gt O TKMU0404 BAR MOUNT KIT SHORT 1 REQ D STANDARD 11A TKMU0403 BAR MOUNT KIT TALL 1 REQ D ACCESSORY BCKG0023 ALLOY BRAKE LEVER W BALL ACCESSORY BCKG0024 BRAKE PERCH ASSY W LEVER amp BALL ACCESSORY BAKGOOO4 SHIELDED BRAKE HOSE ASSEMBLY 16 85 RCMUO085 92 RCMUOO92 99 RCMUOO99 86 JRCMUO086 93 RCMUOO93 100 RCMU1100 00060 RCMUO065 Pot Romuooe2 Tes RcMuooss T
32. MP CRANK 14 HCNS1001 M10 NUT 15 50001 IGNITION COVER 16 ZCCS0002 GASKET IGNITION COVER 17 HCBCO402 M4X35mm SHCS 4 REQ D 18 ICMU0012 WOODRUFF KEY NOT SHOWN ACCESSORY ICMU0017 SPARK PLUG CAP 0 Q 19 Parts Engine Bottom End and Transmission Engine Bottom End and Transmission REF PART DESCRIPTION 1 amp 2 EKCS0003 ENGINE CASE SET W B amp S 50 2012 3 ZCCS0005 GASKET CRANKCASE CENTER 4 0605 M6X40mm SOCKET HEAD SCREW 6 REQ D 5 HCBCO608 M6X55mm SOCKET HEAD CAP SCREW 1 REQD 6 0606 M6X45mm SOCKET HEAD SCREW 2 REQ D 7 ECMU0038 CRANKSHAFT 8 ECMU0016 BEARING CRANKSHAFT 9 ECMUO118 SEAL CRANKSHAFT 10 HCDP1401 DOWEL ENGINE CASE ALIGNEMENT 2 REQ D 11 DECMUO999 OUTPUT SHAFT TRANSMISSION WITH GEAR 12 ECMUO100 SECONDARY SHAFT TRANSMISSION WITH GEAR 13 ECMUO001 BEARING TRANMISSION SECONDARY SHAFT 14 0031 BEARING OUTPUT SHAFT RIGHT SIDE 15 HCBHO612 M6X12mm HEX HEAD SCREW BEARING RETAINER 2 REQ D 16 HCWF0316 WASHER FLAT 17 ECMUOO20L BEARING TRANSMISSION PRECISION 18 ECKGBRO1 BEARING TRANSMISSION OUTPUT SHAFT 19 ZCDCORO1 O RING SPROCKET SPACER 20 ECMU0072 SEAL OUTPUT SHAFT 21 ECMU0073 SPACER SPROCKET 22 ECKGSRO03 SNAP RING SPROCKET 23 0013 SPROCKET 13 T STANDARD 23 0012 SPROCKET 12 23 0014 SPROCKET 14 T 23 PCKGOO15
33. NGE HEAD BOLT CHAIN ROLLER WIDE FOOTPEGS PAIR KING STYLE M8X40mm FOOTPEG BOLT 2 REQ D M8 LOCKNUT 2 REQ D 8mm FLAT WASHER 2 REQ D FOOTPEG SPRINGS SINGLE PIECE 2 REQ D BRAKE PEDAL PIVOT BOLT M6X16mm SOCKET HEAD CAP SCREW FCEX0018 BRAKE ADJUST ECCENTRIC Parts Frame Mounting Hardware Il Frame Seat Fender Right Side Panel Radiator amp Shock Mounts REF PART DESCRIPTION FACJ2012 FRAME CX50 JR HCBF1040 M10X40mm FLANGE HEAD BOLT 0001 MOUNTING BRACKET RADIATOR BOTTOM M6X55mm SOCKET HEAD CAP SCREW M6 LOCK NUT 6 MCKGGROO GROMMET RADIATOR MOUNT 2 REQ D ON BOTTOM 2 ON TOP BRACKET MOUNTING BRACKET RADIATOR TOP 2 REQ D 8 HCBC0665 6 65 SOCKET HEAD SCREW 9 HCBF0616 M6X16mmFLANGEHEADBOLT 29 Parts Front Brakes AR l IT 34 REF PART DESCRIPTION 6 X JBKKGOOOT KITBRAKEPADS WITH E CLIP 8 0501 5 12 SOCKET HEAD CAP SCREW 6REQD 9 640 M6X40mm FLANGE HEAD O RING BLEEDER 2mm SPECIAL 30 Parts Front Wheel Front Wheel PART DESCRIPTION WHEEL WITH BEARINGS SPOKE STYLE FRONT AXLE M5X12mm SOCKET HEAD CAP SCREW 6 REQ D BRAKE ROTOR FRONT 6 WCMU0120 JBEARING WHEEL 2REQD 8 WCCJO03 WHEEL SPACER RIGHT LONG 9 HCWF1202 WASHER AXIE FRONT TIRE 10 X 2 50 DUNLOP MX51
34. PRING KICKSTART 20 ZCMUB014 O RING KICK SHAFT 2 REQ D 21 HCWS1622 SHIM KICK SHAFT 22 ECDC0036 SNAP RING KICK SHAFT 23 ECMU0130 KICK LEVER W BOLT 24 ECMUO250 WASHER KICK LEVER MOUNTING 25 HCFHO625 M6X25mm FLANGE HEAD BOLT 26 ECMU0115 CLUTCH COVER 27 ZCMU0030 CLUTCH COVER GASKET 28 ECMU0168 OIL FILL PLUG ALUMINUM 29 ZCMUB014 O RING OIL FILL PLUG 30 HCBC0608 M6X55mm SOCKET HEAD CAP SCREW 6 REQ D 31 ECMU0207 KICKSTART GEAR SMALL 32 ECMUSP01 KICK START DOG SPRING PAPER CLIP J SPRING ACCESSORY HKCP0001 10 PACK OF COTTER PINS HCCP0002 ACCESSORY 00002 KICKSTART PIVOT KIT SPRING BALL SCREW 21 Parts Engine Water Pump Engine Water Pump REF PART DESCRIPTION 1 EKMUO011 WATER PUMP KIT WITH IMPELLER 2 ECKG0142 SHAFT WATER PUMP 3 ECKGOO72 BEARING WATER PUMP 4 ECKGO0074 SEAL WATER PUMP SHAFT 5 ECKGO0073 IMPELLER WATER PUMP ALUMINUM 6 HCBC1512 M5X12mm SOCKET HEAD CAP SCREW STAINLESS 7 ECMUO167 BEARING WATER PUMP BIG 8 ECKGO175 WATER PUMP PULLEY FAN TYPE DRIVEN 9 ECMUO180 BELT RETAINER 10 HCBS0003 SHOULDER BOLT 6mm 11 ECKGO170 WATER PUMP BELT 12 ECKG0042 WATER PUMP PULLEY CRANK 13 HCNS1001 M10 NUT 14 HCBC0408 M4X8mm SOCKET HEAD CAP SCREW BLACK OXIDE 15 HCWF0401 4mm WASHER 22 Parts Engine Top End Ce 12 a Engine Top End
35. R premix oil with high octane pump gas mixed at 40 1 150 ml oil to 2 gallons of gas Other brands of oil should be mixed at 32 1 for break in LUBRICANTS CAUTION Failure to use proper fuel oil or fuel oil mixture may result in premature engine wear or damage to the machine Adhering to the following break in schedule will result in long lasting high performance machine e Start bike on stand e First 5 minute period operate the bike on the stand with a combination of idle and high RPM operation avoid prolonged high RPM but spin the rear wheel good at least once or twice per minute e Allow bike to cool e Ride for 15 minutes maximum avoid prolonged high RPM operation and avoid abusing the clutch with throttle blipping e Allow bike to cool and inspect bike for loose fasteners e Avoid prolonged operation at Wide Open Throttle for the next half hour e After 1 hour of operation o Check for loose bolts and nuts o Clean the carburetor bowl o Change the transmission clutch lubricant e Check CFD torque and adjust as necessary e After 8 hours of operation o Change the fork oil o Have a Certified Cobra Mechanic or suspension specialist change the shock oil e Your bike is now ready for the highest level of competition NOTE During break in the bike will likely lose some engine coolant through the radiator overflow hose Losing up to 4 oz 120 ml is normal Proper coolant level will cover the top of the radiator cores Removi
36. W 4 REQD 20 HCBF0616 6 16 FLANGED HEAD W 8mm HEX 21 0825 8 25 SHCS 4 REQD 22 00011 STEERING HEAD RACE 2REQ D 25 Parts Forks Leg Assembly Brake Side PART DESCRIPTION REF DESCRIPTION _________ 10 11 11 11 12 13 14 15 16 17 Parts Forks Leg Assembly Non Brake Side REES PART DESCRIPTION 6 X JKCKGOOS1 FORKBUSHNG amp jj 8 0052 FORKWIRERETAINER 9 0008 FORKSWIPER30mm 1 1 jj 27 Parts Frame Mounting Hardware l Frame Engine Swingarm Tank and Pipe Mounts 14 15 16 17 18 19 20 21 22 23 24 25 26 27 PART WCMUO016 HCNL 1201 HCBHO880 HCNLO801 MCMUGRO2 HCBF0635 0003 0004 0601 0006 HCBFO685 HCBB0635 HCBF0620 HCNF0602 HCBFO625 MCMUGRO03 TCKG0001 HCWF1478 HCBF0616 FCC60020 00010 HCBHO840 HCNLO802 HCWF0803 TCMU0107 BCDCO0009 HCBCO601 DESCRIPTION SWINGARM BOLT M12 SWINGARM LOCK NUT M8X80mm SOCKET HEAD CAP SCREW M8 LOCKNUT GROMMET KIT PIPE amp SPACER M6X35mm FLANGE HEAD BOLT 6mm CLIPNUT BUSHING REAR TANK MOUNTING M6 LOCKNUT BUSHING FRONT TANK MOUNT 2 REQ D M6X85mm SOCKET HEAD CAP SCREW M6X35mm BUTTON HEAD CAP SCREW M6X20mm FLANGE HEAD BOLT M6 NYLOC FLANGE NUT M6X25mm FLANGE HEAD BOLT GROMMET SILENCER 2 REQ D SPACER FOR EXHAUST GROMMETS WASHER EXHAUST GROMMET M6X16mm FLA
37. a Frictional Drive slips 1 Access the slip clutch by draining the oil and removing the cover exposing the CFD 2 Brace the CFD gear from turning with a suitable device Cobra tool EAMU0004 or similar 3 Install the Sprocket Socket CFD torque checking tool MCMUTL15 on the sprocket and secure with the supplied screw and ensure that the tool is completely up against the sprocket 4 Verify with a torque wrench applied to the Sprocket Socket that the V3 CFD does not slip below 81 Nm 60 ft Ib in either direction 5 If there is slippage below 81 Nm 60 ft Ib remove the cotter pin and tighten the nut on the CFD one more position it is a hand thread nut so you must turn it counter clockwise 13 CAUTION Do not check earlier versions of the CFD with this method The torque valves required at the sprocket would be much higher HINT This V3 CFD torque checking method is possible do to with the chain on Just put the bike on a stand so that the rear wheel can turn freely HINT The CFD hubs can be removed with the universal puller MCMUTL70 14 Parts Parts Airbox and Inlet System 15 Airbox and Inlet System REF PART DESCRIPTION 1 ZCCS0001 GASKET REED TO CYLINDER 2 ECMUO246 REED CAGE ASSEMBLY WITH REEDS VFORCE 3 RCCS0002 INLET MANIFOLD 4 HCWF0601 6mm FLAT WASHER 5 HCBC0603 M6X30mm SOCKET HEAD CAP SCREW 6 MC
38. arts Engine Bottom End and 20 Parts Engine Clutch and Kicker 21 Parts Engine Water Pump 22 Parts Engine Top End AAA 23 Parts Exhaust System ERR 24 Parts Forks amp Triple Clamp 2 221 25 Parts Forks Leg Assembly Brake Side 26 Parts Forks Leg Assembly Non Brake Side 27 Parts Frame Mounting Hardware 28 Parts Frame Mounting Hardware ll 29 Parts Front Brakes uu Dm 30 Parts FROME Wheel n A E 31 le 32 Parts Rear 2 0 0 00 01 0 S N sere 33 Parts sear Wheel caes sec a 34 Pants SOCK EE 35 Parts Shock Inside EE 36 Parts Swingarm Assembly 37 SEVICE Lui as si eod renovar dde oeufs aaa khas visere 38 Eri ine ele 38 Base Gasket Selection
39. e Glycol based coolant antifreeze solutions Fuel amp Air System Carburetor Tools recommended for carburetor service e Small flat head screwdriver e WD 40 e 8mm socket Your Cobra is equipped with an adjustable carburetor Some fine tuning may be needed according to weather condition and altitude Proper jetting is very important for engine performance and engine life Serious damage to the engine can occur if not properly adjusted IDLE ADJUSTMENT On the left side of the carburetor there are two adjustment screws The larger screw with the knurled head is the idle adjustment screw To raise the idle turn the screw in clockwise in 1 4 turn increments and rev the engine after each adjustment To lower the idle turn the screw counter clockwise TOP END JETTING Indications that the engine is running too rich too much fuel for the air are e Engine not revving out or blubbering at high RPMs e Engine will not clean out Wet or black spark plug NOTE Before changing jetting be sure that the air filter is properly cleaned and has the usual amount of air filter oil An overly dirty air filter can cause the engine to run rich If the engine is running rich on the top end it should be leaned out Leaning it out can be done by 1 Changing the main jet to a smaller number 2 Raising the needle clip this lowers the jet needle one notch at a time on the slide 55 Indications that the engine is running too lean
40. e hammer with e fitting to thread into threads on end of shaft M5x1 0 e single and double hook ends for removing plastic impeller Dead blow hammer COBRA IMPELLER SERVICE INSTRUCTIONS d Remove radiator cap and drain engine coolant as described above NOTE If the impeller is damaged or broken completely back flush the coolant system to ensure no solid pieces are in the system 2 3 Remove ignition cover using a 4mm hex key four places Stick a 3mm hex key in the water pump shaft cross hole and remove belt retainer screw using a 4mm hex key Figure 42 item 1 4 Remove belt retainer water pump belt and water pump fan pulley 5 6 Thread a slide hammer onto the end of the water pump shaft and remove the Remove bearing retainer screw using a 3mm hex key assembly NOTE It is quite common for the older plastic impellers to fall off the end of the shaft during this step of the process if that is the case then follow the steps at the end of this section to remove the seal and impeller fi Clean anv debris or particles from the bore and use some light emerv cloth to remove anv scratches in the surface that the removal process mav have created Lubricate the bore with grease 53 9 Prepare for assembly by installing the water pump assembly into the assembly tool and align the tool with engine case making sure alignment pin is in proper hole CAUTION Damage may occur if one attempts to install the
41. ed 6 7 ii Wrong spark plug installed 8339 Champion to be used on 04 or later amp no mods iii Spark plug cap off iv Engine Shut off kill switch is shorted v Bad electrical ground vi Stator winding damaged d Exhaust is plugged Overheating a Bad stator b Water pump pulleys or belt broken c Water pump impeller broken or bolt out d Jetting too lean e Too much throttle blipping f Too high gearing g Kinked radiator hose h Rear brake dragging i Chain too tight j Airleak Engine won t idle a Idle knob needs adjusted b Air leak C Carburetor jets are dirty 68 Index Air Filter Maintenance 11 Frictional Drive 13 Airbox Front Brake xis A 15 30 Bars and Controls 16 Front Forks Base Gasket Selection 39 63 6 Front FOrKS Eege 63 Carburetor Front Wheel Parts 31 ui c M 17 Fuel System Service 54 Service 54 Specifications 4 59 seed tette tede 63 Hardware and Fasteners CFD Cobra Frictional Drive 13 Frame 28 Chain Eege red Eege 32 Adjustment 11 Ignition Chassis
42. ed or mostly closed throttle to a larger throttle opening Observe the rich and lean symptoms listed above Adjust the jet needle position by moving the clip from its current position move the clip higher on the needle to make the bike run leaner or move the clip lower on the needle to make the bike run richer to one higher or lower 66 Troubleshooting 1 Engine not behaving properly 2 3 4 5 a b c d e f Carburetor top is installed backwards happens a lot The carburetor slide indexing pin is missing Wrong spark plug installed 8339 Champion to be used on 04 or later amp no mods Needle clip is on top of plastic not below Air leak find where with carb cleaner or similar Ground wire or ignition leads have fault Engine is down on power a b c d e f 9 Clutch engagement is not set properly Jetting is incorrect Silencer needs repacked Exhaust pipe i Has excess carbon buildup ii Has large dent in it Compression is low i Piston ii Rings Reeds are damaged Ignition timing is incorrect Engine is excessively loud a Silencer needs to be repacked Engine cuts out at high RPMs a b c d Stator bad Carburetor diffuser plate upside down install like a skirt Plugged fuel petcock Silencer core tube broken Engine won t start a b c Fuel i None in tank ii Is sour or bad Carburetor is dirty Ignition i Spark plug foul
43. ed as possible Be sure the fuel tank and carburetor have been removed and safely located away from the welding process The frame is 4130 Chrome Moly and it is important to weld it with the proper rod and heat settings set as light as possible Cobra recommends replacing the frame with a new one if the old one becomes damaged Use ER70S6 filler if welding on the frame If your kick starter lever does not return properly first try loosening the six kick clutch cover screws 75 turn Hold the kick lever gt way down while retightening the six screws starting for the center and working out Inspect CFD slip torque every 10 hours of riding Check proper clutch engagement before and after each ride If the clutch is engaging properly DO NOT feel the need to take the clutch apart to measure the spring stack clean the stack replace the springs etc Cobra has worked very hard to make a clutch that is low maintenance and so only take it apart if it NEEDS to be maintained Schedule Prior to each ride Check that the air filter is cleaned and oiled Insure the smooth operation of the throttle cable Check for frayed strands of the throttle cable inside the throttle housing Check for adequate tire pressure Check all nuts and bolts for proper torque Spray all moving parts with WD40 or other light oil Check drive chain for Proper tension Adequate lubrication Insure that the ignition stator and rotor are clean and dry o Check the f
44. erated by the clutch and engine during extended periods of riding it is advisable to remove the ignition cover afterward to allow the ignition to cool off The heat transfers through the cases and can damage the stator as it cools off because of lack of airflow around the stator e Ignition will overheat if the gap between the rotor and stator is not large enough There should be even clearance as the rotor rotates relative to the stator e Non resistor spark plug caps should be used Resistor caps will result in a weaker spark that will reduce performance e Make sure connections are free of dirt The proper ignition timing for this model of is at 0 035 before Top Dead Center that means 0 035 before the piston reaches the highest point of it s travel in the cylinder CAUTION Advancing the ignition timing will cause the engine to run hotter in turn causing power loss shortened clutch life and possibly lead to premature stator failure and can also cause detonation which can lead to premature piston and ring failure Tools recommended for timing service e Compact motorcycle dial indicator e Universal clutch puller a universal puller that pulls the clutch main drive gear and rotor Part MCMUTL70 TIMING YOUR IGNITION Remove the spark plug Insert the dial indicator into the spark plug hole Remove the four bolts from the ignition cover Remove the water pump belt from the rotor and water pump shaft Turn the cran
45. f their weight A No there is one best setting and it works for light or heavy riders Q If my clutch basket changes color should l replace it A If it is blue or purple replace it If it is silver or brown you are fine Cobra is now going to greater lengths to ensure that the clutch on your motorcycle is performing the best possible from the shop and so it may have a different clutch stack or shim washer from what you are used to Please take measurements for knowledge sake but don t blindly restack washers to different heights without first consulting the factory Cobra clutch puller assembly 6mm Puller hole mm Puller hole FL b s gt En Apply heat here So e lif necessary Um d A i 2 1 E ra j 6mm Puller hole D gt Figure 36 Figure 37 Clutch puller installation 46 Tools recommended for clutch service e Universal clutch puller a universal puller that pulls the clutch main drive gear and rotor Part MCMUTL70 e 5mm T handle e Clutch nut removal tool ECMU0078 amp spanner wrench ECMUOO82 e Cobra 3 Shoe Clutch Milk Part MCMUGF32 Clutch Removal Drain the engine transmission oil and remove the clutch cover 2 Remove the clutch nut not left hand thread on the end of the crankshaft with the clutch nut removal tool 3 Attach the Universal Puller There are three 6mm clutch puller holes located on the ends of the center hub figures 36 amp
46. haft 5 Remove the stator 4mm Allen 6 Remove the left hand thread blue nut holding the CFD to the transmission input shaft 19 mm socket 7 Remove the special nut starter gear that holds on the clutch special tool available contact your local dealer 8 With the Cobra flywheel clutch puller 68 remove the clutch from the crankshaft details in Clutch Service portion of this manual Top End Disassembly Procedure 1 Remove the cylinder head nuts 10mm 2 Remove the cylinder head outer 3 Remove the cylinder head insert INSPECTION NOTE Inspect the cylinder head for deposits and abrasions 1 If there are deposits they should be removed a Black oily deposits indicating a rich mixture or improper oil type quantity can be removed with solvent b Crusty deposits indicating dirt ingestion can be removed with solvent and may require some scraping 2 Abrasions a Pitting or erosion indicates detonation and may require cylinder head replacement also i Retard the ignition timing i Use a higher octane fuel b Missing chunks or indentations indicate broken hardware or ingested items replace the cylinder head 4 Remove the cylinder INSPECTION NOTE Inspect the cylinder bore for abrasions deposits and missing coating 1 If abrasions scrapes scratches pitting etc are found replace the cylinder 2 If deposits all are found a Clean with muriatic acid b Once the deposit
47. he engine with either 1 the crankcase stamp recommended base gasket or 2 if assembling with a new set of cases assemble with a 0 4mm 0 015 base gasket and torque the head nuts to the proper torque specifications leaving off the spark plug and ignition cover piston rings can be left off to ease assembly e Carefully insert the solder wire though the spark plug hole into the cylinder far enough such that the tip of the wire touches the left or right side cylinder wall not the front or back as the piston will rock more and give incorrect measurement e Hold the wire at this position and rotate the crankshaft by the flywheel nut or kick lever three revolutions to crush the solder wire to be measured CAUTION If you rotate the flywheel nut in a counterclockwise direction there is a risk of loosening the nut e Pull out the wire and measure the solder thickness at the thinnest location near its tip accurately with the thin tips of calipers e Adjust base gasket thickness as necessary to get the desired value Upon completion your final assembly squish clearance should agree with the chart below Measured Squish Clearance minimum These numbers only apply when measured as described above 0 020 0 026 0 50mm 0 65mm Risk Best performance Loss of Torque Over rev of damage performance 40 Engine Removal To service the bottom end transmission the engine must be removed from the frame Tools required 10 11 13 22
48. he threads of the clutch nut If you are using an impact socket just zap it lightly with an air wrench to tighten it because there are only about 4 threads inside the nut and they can be easily stripped If you are tightening it by hand you can hold the crank from turning with the clutch removal spanner ECMU0082 Install the clutch cover tightening the bolts from inside out 8 or 10 mm socket 5 8 ft lb 7 8 Nm INSPECTION NOTE There must be in out play in installed clutch 0 4mm to 1 0 mm 0 015 to 0 040 Excess in out will cause early crank seal failure A blue clutch drum is worn out from excessive slippage or improper lubrication NOTE To ensure proper engagement of the kick gear with the starter nut tighten the six screws only to the point of being not extremely loose Using one hand rotate the kick lever to 7 stroke and hold while tightening the six screws completely with the other hand Fill with oil 235 ml 8 0 oz Cobra 3 Shoe Clutch Milk Part MCMUGF32 Ignition Stator care Stator failure will result from running the bike hot Following is a list of things that will make your engine run hot 1 The timing should not exceed the maximum specifications listed 2 Improper carburetor jetting 50 3 Improper spark plug heat range Never run a hotter plug than the specified spark plug 4 Clutch slippage See CLUTCH section for causes of slippage CAUTION e Because of the amount of heat gen
49. hine will produce a spark plug that is dry and light tan in color 64 Environmental and altitude related mixture adjustments Condition Mixture will be Required adjustment Cold air Leaner Richer Warm air Richer Leaner Dry air Leaner Richer Very humid air Richer Leaner Low altitude Standard None High altitude Richer Leaner Low barometric pressure Richer Leaner High barometric pressure Leaner Richer NOTE Before making any carburetor jetting changes verify that o You are using the proper fuel and oil The fuel is fresh and uncontaminated The oil and fuel have been mixed in the proper ratio The carburetor is clean no plugged jets The air filter is properly clean and oiled The float height is within proper specification proper measuring technique is described later in this section O O OOO NOTE Perform all jetting changes on a motorcycle that has been warmed up to proper operating temperature The carburetor on your Cobra motorcycle is quite adjustable Figure 59 shows its range of adjustment and in particular what adjustable component affects what range of operation specifically throttle position mana l 4 Clip Position 4 Straight Dia gt TEENS ix Needle Taper uU uU Lo A lt o z k 4 Throttle Valve us WE Cut awav e LL LM S Air Screw Slow Jet Slow A
50. ir Jet l IDLE 1 8 1 4 1 2 3 4 W OT Figure 59 Throttle Opening FUEL SCREW ADJUSTMENT Adjust for maximum idle speed The fuel adjustment screw is located on the left side of the carburetor It is the smaller of the two adjustment screws and requires the use of a small flat blade screwdriver for adjustment After adjusting for maximum idle speed use the idle screw to adjust the desired idle speed NOTE If the fuel screw requires more than 3 turns out replace the pilot jet for one that is one size richer larger number then re adjust the fuel screw IDLE ADJUSTMENT Adjust for desired idle speed The idle speed screw is located on the left side of the carburetor It is the larger of the two screws on the side of the carburetor and is unique with its knurled head for easy fingertip adjustment To raise the idle turn the screw in clockwise in 1 4 turn increments and rev the engine after each adjustment To lower the idle turn the screw counter clockwise TOP END JETTING Adjust for clean full throttle acceleration Jet your top end main jet based on the acceleration of your Cobra Motorcycle on the longest straight at the track Observe any of the lean or rich symptoms spark plug appearance and bike performance listed above and change your jetting accordingly PART THROTTLE Adjust for desired acceleration Using an area of the track that allows the rider to operate and mid throttle and transition accelerate or roll on from clos
51. kshaft counterclockwise until it reaches top dead center e poses m 51 Figure 39 Lining up the line on the rotor Figure 40 Using a dial indicator to measure with the line on the stator piston height for setting ignition timing Set the dial indicator to zero Turn the crankshaft clockwise until the dial indicator reaches 0 035 0 9mm from top dead center At this position the line on the rotator should align with the center of the stator Coil at 5 o clock position on stator frame If not loosen the three 5mm bolts to adjust the stator ROTOR INSTALLATION 1 pisse N Torque the nut on the rotor to 30 ft Ib 45 Nm with high strength red thread locking agent Recheck the timing following the procedure of timing your ignition Install the water pump belt back on Bolt the ignition cover back on Put the spark plug back in and firmly stick the spark plug cap onto the spark plug Cooling System Radiator fluid removal Remove the coolant drain plug 13mm bolt on the front of the engine cases NOTE Inspect the old coolant for evidence of oil combustion byproducts black oil slick stuff or other things that may indicate a problem 52 Tools recommended for impeller service Flat head screwdriver 13mm hex wrench 3mm hex key 4mm hex key 5mm hex key 8mm hex key Water Pump Installation tool MCMUTLOS 2010 and newer JR amp King MCMUTLOS 2009 and older JR models Slid
52. mm wrench e 1mm flexible solder material e measurement calipers When rebuilding the top end of your Cobra motorcycle care must be taken to ensure the proper squish clearance Squish clearance is defined as the minimum distance between cylinder head and piston at TDC There are negative effects of either having too much or too little clearance Since parts like the crank connecting rod cylinder head piston and crankcases all have varying tolerances Cobra offers several different base gasket thickness to ensure that you can always set the squish clearance of your engine to factory specifications For base gasket replacement use the code see figure 31 for location along with the table below to reorder the correct thickness gasket Base Gaskel Code Stamped Here Figure 31 Supplied Base SE Gasket Thickness Cobra ff mm inch Part f 3 0 3 0 012 ZCMUO703 4 0 4 0 015 ZCKGO501 5 0 5 0 020 ZCMUO705 6 0 6 0 024 ZCMUO706 7 0 7 0 028 ZCMUO707 8 0 8 0 031 ZCMUO708 NOTE Tolerances will affect the actual gasket thicknesses 39 If top end parts are changed during the course of the maintenance the squish clearance should be measured and possibly a different base gasket will be required The easiest way to measure squish clearance is with 1mm to 1 5mm thick flexible solder wire available through most popular electronic stores The process is as follows e Assemble the top end of t
53. mmable solvent to remove the filter oil Do not clean the air filter with gasoline or other highly volatile petroleum product Diesel fuel or kerosene would be preferred but caution should still be taken Hot soapy water works well 5 Clean the filter in hot soapy water to remove all dirt particles 6 Allow it to dry thoroughly 11 7 Saturate with filter oil and remove excess NOTE The Cobra is equipped with a special designed Air box It is very important to keep the air filter clean and properly oiled with high quality water resistant foam filter oil It s very important to oil your filter consistently each time because varied amounts of oil will change your carburetor jetting 8 Reinstall the filter boot assembly making sure the letters CM are visible between the carburetor and air box figure 4 Figure NOTE Make sure you change or clean your filter after each ride Fork Oil Replacement Tools required e Two 19 mm wrenches or sockets e 4 amp 5 hex key Allen wrench e 25mm wrench or socket e 20 wt fork oil Disassembly procedure Remove the front wheel 19 mm wrench Remove the brake caliber from the fork leg 4 mm hex key Loosen the fork caps 25mm socket Remove the fork legs from the triple clamps 5 mm hex key One leg at a time Remove the fork cap from the leg Separate the fork cap from the damper rod Pull out the fork spring Place upside down over a suitable pan tray or co
54. n when accelerating off idle ii Motorcycle moves but not with much power iii Clutch fully engages before the power band kicks in 2 Things to measure that can have an effect a Spring washer configuration b b Spring stack without flat washer C Thickness of flat washer d Individual spring washer thickness e Individual spring washer height f Effective bolt shoulder length e Shoe thickness difficult to measure accurately can only be approximated by the size of the step where it sticks out of the basket e Basket has worn and is too large There is a relationship between observed characteristics and the things that can be measured If a clutch comes in too early it means that clutch spring stack is not providing enough force to keep the shoes from being thrown out to the clutch basket at the proper time with the given shoes basket arbor and bolt This can be due to i Clutch spring stack is to short 1 Wrong configuration 2 Sacked out over stressed washers 3 Too thin a flat shim in the stack ii Spring rate too low wrong configuration with proper stack height iii Clutch arbor shoulder bolt is too long If a clutch comes in too late it means that clutch spring stack is providing too much force to keep the shoes from being thrown out to the clutch basket at the proper time with the given shoes basket arbor and bolt This can be due to i Clutch spring stack to tall 1 Wrong configuration 2 To
55. ng the radiator cap and looking inside is the only way to check the coolant level Never remove the radiator cap of a machine that has a warm engine Burning and scalding could occur Starting Procedure Before starting the machine inspect the following Tire pressure Chain tension Coolant level Proper wear on chain rollers and sliders Handlebar tightness Throttle assembly movement cable adjustment Air Filter Check for loose nuts and bolts Turn the fuel on by rotating the fuel petcock knob to the vertically downward position reserve position is horizontally forward NOTE For best results from your Cobra Motorcycle use only the recommended fuel Testing has shown that most race fuels actually degrade performance Always wear a helmet and other protective riding gear When your pre ride inspection is complete the bike may be started For a cold engine follow this procedure 1 Place the motorcycle on a stand of sufficient strength that positions the motorcycle in a level upright position with the rear wheel off the ground 2 Pull up the choke knob and turn it to lock it 3 Kick start the engine 4 Rev the engine in short spurts turning the throttle no more than 1 4 open until the engine will run without the choke 5 Verify a functional engine shut off switch by shutting off the engine 6 Restart the engine and proceed with riding when the engine is sufficiently warm i e the side of the cylinder is warm to to
56. ntainer Work the damper rod up and down several times Allow it to drain completely gu I e o o Assembly procedure 1 Fill the left brake side fork leg with 4 0oz 120 ml 2 5 wt fork oil and fill the right non brake side fork leg with 2 0 oz 60 ml 2 5 wt fork oil 12 2 Measure the fork oil level to the top of the fork tube with the leg collapsed and record for tuning purposes 3 Install the fork spring 4 Reconnect the damper rod to the fork cap 12 ft Ib 16 Nm CAUTION The damper rod is hollow and will break if the nut is over tightened 5 Reinstall the for cap into the fork leg 5 ft lb 6 7 Nm 6 Reinstall the fork legs into the clamps 6 ft Ib 8 Nm 7T Reinstall the brake caliper 8 Reinstall the front wheel 25 ft Ib 34 Nm Cobra Frictional Drive V3 CFD The Cobra Frictional Drive CFD is essentially an adjustable slip clutch that dissipates torque spikes transmitted from the rear wheel to the rest of the drive line and engine Instead of these torque spikes potentially damaging internal components the CFD allows the transmission to slip with respect to the engine For this to occur the CFD must function properly by slipping above a minimum torque value The safe minimum slip torque of the CFD should be checked every 2 hours of operation The slip torque value should be above 60 ft Ib 81 Nm measured at the sprocket To properly measure the minimum torque at which the CFD Cobr
57. o handle the harsh environment of the automatic clutch and transmission of this motorcycle Cobra s specially developed Cobra Venom 3 Shoe Clutch Milk Part MCMUGF32 was formulated to provide superior lubrication and cooling capability over extended periods of time and is the recommended lubricant for your Cobra motorcycle 10 Proper Chain adjustment Tools required for chain adjustment 19 wrench or socket e 13mm wrench or socket 1 Make sure that the rear wheel is aligned properly 2 A properly adjusted chain will have 50mm 13 8 free movement behind the chain block with no load on the bike figure 2 Figure 2 3 Sit on the bike and verify that the chain has a minimum of 12mm 1 2 free movement when the chain is at it s tightest point 4 Ifthe chain requires adjusting loosen the axle with a 19 mm wrench and tighten the chain by rotating the adjustor bolts clockwise CW or loosen the chain by rotating the adjustor bolts CCW 5 Retighten the axel bolt to 25 ft Ib 34 Nm ELLE 6 Retighten the adjustor bolt Air Filter Cleaning Tools recommended for air filter maintenance e 2 Phillips head screwdriver e 4mm Allen wrench e Foam filter oil Procedure 1 Removed the seat with a 4 mm Allen wrench 2 Remove the filter air inlet boot from the back of the carburetor with a Phillips screwdriver 3 Pull the filter boot assembly out the top of the air box 4 Clean the filter in a nonfla
58. o thick a flat shim in the stack ii Spring rate too high wrong configuration with proper stack height iii Clutch arbor shoulder bolt is too short iv Clutch shoe material has worn too thin v Clutch basket has worn too much and is too large of a diameter With the exceptions of component failures generally two things will occur 1 The clutch shoes will wear causing the clutch to engage later and 2 The springs will sack causing the clutch to engage earlier Typically the springs will sack at a quicker rate than the shoes will wear meaning that an un tampered clutch that worked fine will ultimately hit too early at some time When this occurs it is easily remedied with a new spring stack or a thicker flat shim Because the shoes have worn a thinner flat washer may be needed with the fresh new springs to allow proper clutch engagement One thing to remember If your clutch is hitting fine don t mess with it 59 Some things to remember to aid clutch life Change oil each ride Gear to the low side Avoid mud if possible Cut mud practice to 1 lap or none Stay on the gas no throttle blipping Run more air pressure to allow wheels to spin helps throttle steer Make sure wheels spin freely no bent rotors dragging brakes chain too tight etc Make sure the engines pulls cleanly and strong by having properly maintained engine with correct ignition timing and carburetion Also refer to the Clutch Service section of this
59. r Shock eere torni eer 62 Rear Wheel 34 SHOCK a A ceed 35 36 Swingarm 37 Top End 23 Triple Camps 25 Parts List Front Forks 63 Plastic amp Seat Parts 32 rtr 57 Rear Brake EE 33 Rear Wheel xd n SERE A A 34 70 PUEIS A 57 Reeds PERRA 56 SHOCK inu decus cete aiu quiu quis dl Dio Bs 62 Paris eese 35 36 Slip Clutch 13 Spark Plug Recommended 4 Specifications 4 torque values 5 SLAG eoe teet 7 Swingarm 37 Top End ali AP 23 Service 38 Torque Values 5 Transmission Specifications 4 Transmission Lubricant Replacing 10 Troubleshooting 66 Sg me u TP 63 VIN reading 8 WARNING 1 Water Pump PR 22 Wheels SOM OO E 57
60. r end sways on straights Harder compression damping Bike tends to jump rear end high Harder rebound damping Bike tends to jump rear end low Softer rebound damping Frequent rear end bottoming Harder compression damping Bottoms after end of continuous bumps Softer rebound damping Rear end kicks over square edge bumps a Harder rebound 2 Softer ompression 62 Proactive Suspension Adjustments Once you have the suspension adjusted for decent overall feel you can make proactive adjustments when faced with different racing conditions Situation Actions Sand track Lower the rear end increase race sag Sand track Stiffer compression and rebound damping Long fast track Lower the forks in the clamps by 3 mm Tight slow track Raise the forks in the clamps by 3 mm Mud track Lower the bike if the rider has difficulties touching the ground Rear shock The rear shock on your Cobra is adjustable to your riders weight and riding style by changing the spring rate stiffness of the spring and or by changing the damping valves Due to the complexities of the shock absorber internals Cobra recommends that you either send the shock back to us for damping valve changes or send the shock to a competent suspension specialist such as PR Cobra offers stiffer and softer shock springs depending on the weight of your rider See the Parts Shock section or the Optional component section at the beginning of the man
61. rame for cracks the metal or cracks in the paint that might indicate that the metal has been stressed beyond it s safe limits o Check the rims for signs of stress like cracks around the rim spokes and hub o Equalize the pressure in the forks with atmosphere Every 2 hours of operation o Replace the transmission oil Every 10 hours of operation o Replace the fork oil o Have the shock oil replaced by a Certified Cobra Mechanic or a suspension specialist O O OOO O O Replacing Transmission Clutch Lubricant Minimum of 235 ml 8 oz Cobra Venom 3 Shoe Clutch Milk Part f MCMUGF32 Up to 350ml 12 oz can be applied without hurting performance Tools needed e 8mm allen wrench Procedure 1 Begin this procedure with a bike that has been ridden more than 5 minutes but less than 10 minutes 2 Remove the oil drain plug on the clutch cover near the brake lever figure 1 OU Fill grr dn LI Figure 1 3 Allow the oil to drain completelv then reinstall the oil drain plug 4 Remove the oil fill plug and add 8 00z of Cobra Venom Shoe Clutch Milk thru the oil fill plug NOTE Applying additional oil up to 350 ml 12 oz can help clutch life More than 350 ml 12 oz will degrade engine performance NOTE It can be helpful to lean the bike over on its left side to add oil to the bike 5 Reinstall the oil fill plug NOTE Cobra has spent considerable time and money developing the proper lubrication t
62. re than 0 64mm 0 025 13 Install the base gasket CAUTION See base gasket selection at the beginning of service section 14 Install the cylinder being sure that the piston rings are properly AET aligned with the indexing pins Os fi 4211 SAA CAUTION Never force the cylinder If resistance is felt determine the problem and solve it Once installed slightly rotate the cylinder d a back and forth insuring that the rings are properly seated pO NE 15 Install cylinder head insert NOTE A light application of silicone grease can help hold the O rings into position during assembiv 16 Install O RINGs as shown in figure 33 17 Install the cylinder head 18 Install the washers with flat side down and nuts Torque to 105 in Ib 12 Nm Figure 33 44 19 Install reed and inlet manifold with new gasket 105 in Ib 12Nm 20 Leak check the engine at 20 psi to ensure proper seal 21 Install stator reinstalling the grommet and wires 22 Install the rotor per Rotor Installation section under the S3 Ignition portion of this manual 23 Install the water pump outlet pipe apply Hi Temp RTV silicon gasket maker to the threads before assembly before installing the clutch and rotate to a vertical position with the engine resting on bench 24 Install the CFD 25 Install the clutch per Clutch Installation section in this manual 26 Install the coolant drain plug with copper washer
63. s are removed inspect for abrasions and missing surface coating i If there are abrasions or missing coating replace ii If all looks well the cylinder may be saved Muriatic acid can be dangerous Follow the manufacturer s instructions closely 5 Remove the piston clip with a scribe 6 Remove the piston pin with a piston pin remover 42 INSPECTION NOTE Inspect the piston for abrasions and deposits on the top and sides and clean or replace as necessary INSPECTION NOTE Piston ring end gap should be between 0 008 0 2 mm and 0 020 0 5 mm Splitting the Cases 1 Remove the fasteners holding the two halves of the crankcase together 2 Separate the cases with a proper case splitting tool CAUTION Take caution when handling the crankshaft It is the main power transfer to the rest of the engine If it is out of alignment it will cause premature failure of your bearings which can lead to serious damage to the cylinder as well as the rest of the engine Do not try to true the crank yourself Truing the crank should be done professionally CAUTION f you split the cases check the gear tooth faces for chipping amp signs of fatigue e Check the small needle bearings for fatigue If the bearings are damaged the engine cases should be checked to make sure the needle bearing casing didn t oblong the bearing hole in the case e Needle bearings should be replaced every 2 months Engine Assembly
64. throughout the travel 2 2 Compression damping optional valve 2 2 1 Harder more damping slower adds resistance to the suspension motion when the suspension is compressing 2 2 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is compressing 2 3 Rebound damping optional valve 2 3 1 Harder more damping slower adds resistance to the suspension motion when the suspension is returning to full length 2 3 2 Softer less damping quicker reduces resistance to the suspension motion when the suspension is returning to full length Front Forks Bottoming Too Frequently Fork oil level If the front forks bottom harshly more than a couple of times per lap and the fork springs are proper for the weight of rider as detailed above try raising the fork oil level in increments of 10mm Raising the fork oil level reduces the air volume and increases the stiffness of the forks late in the travel thus adding a progressive feel Front forks feel too stiff over small bumps Fork oil weight If the forks feel too stiff over small bumps try decreasing the weight increasing the viscosity of the fork oil Rear suspension troubleshooting Damping Always start with standard settings and make damping changes in no more than two click increments and only make one change at a time Symptom Action Rear end feels stiff on small bumps Softer compression damping Rea
65. ual for these other components Shock Preload Shock Damping Adjustment of compression damping 63 Front Forks Cobra offers stiffer and softer fork springs depending on the weight of your rider See the Parts Shock section or the Optional component section at the beginning of the manual for these other components Carburetion Although your Cobra is sent from the factory with the carburetor jetted for optimal performance you may find it necessary to adjustment your particular jetting due to current weather conditions altitude fuel variations and or engine modifications CAUTION Proper jetting is very important for engine performance and engine life Symptoms of improper jetting are listed below e Symptoms of incorrect oil or oil fuel ratio o Poor acceleration o Misfire at low engine speeds o Excessive smoke o Spark plug fouling o Excessive black oil dripping from exhaust system e Symptoms of too rich a fuel mixture o Poor acceleration Engine will not rev out blubbers on top Misfire at low engine speeds Excessive smoke Spark plug fouling o Wet black or overly dark spark plug when removed for inspection e Symptoms of too lean a fuel mixture o Pinging or rattling Erratic acceleration Same actions as running out of fuel High engine temperature White spark plug when removed for inspection O O OO NOTE When inspecting the spark plug to evaluate jetting a properly jetted mac
66. uch CAUTION Never rev an engine full throttle until the engine is at operating temperature This is a high performance race motorcycle Too much application of throttle will likely land your little racer on his or her arse Fenders can be replaced but bruised egos and other body parts take longer CAUTION Make sure your riders foot is not resting on the foot brake while they are riding Maintenance A properly maintained machine is safer faster and more fun to ride Tips 1 Recommended lubricants a Cobra Clutch Milk is by far the best auto clutch lubricant It is a full synthetic lubricant that has been specifically formulated for Cobra s auto clutch and has e Exceptional film strength over petroleum based oils or synthetic blends e Extreme temperature tolerance e NO frictional modifiers e Dispersant package to keep clutch fibers in suspension so they can be flushed out when the oil is changed e Extremely low viscosity for minimal drag and windage b Bel Ray H1 R oil is the recommended premix oil because e Its Ester base leaves a film on all parts at all times No metal to metal startups or corrosion potential e Exception film strength over petroleum based oils or other synthetic blends e Easily atomizes and burns completely e Does not fall out of suspension from premix in cold weather e Produces virtually no coking deposits leaving pistons rings and heads extremely clean with minimal pipe spooge
67. washers also keeps the clutch shoe from engaging fully and this will cause the clutch to start to slip So you will need to clean the sludge out or just replace the spring washers and bolts with new ones How quickly this sludge builds up depends on how often you change your oil and whether your rider is a throttle blipper Clutch Assembly 1 After cleaning or replacing the spring washers reassemble the stack up of washers CAUTION It is also important that all three shoes are stacked the same See figure 38 2 Clean the threads of the stack bolt and the clutch with brake cleaner removing all old thread locking material 3 Apply high strength thread lock material to the stack bolt and tighten to 12 ft Ib 16 N m CAUTION Avoid allowing excess thread lock material to contact the spring washers and the clutch or the clutch is likely to malfunction 49 4 Clean the center hole of the clutch and on the tapered section of the crankshaft 5 Apply a small amount of wicking bearing retainer green thread lock agent to the center tapered section of the crankshaft and taper of clutch arbor CAUTION Lean the bike engine such that any excess thread lock agent goes away from the bushing in the clutch drum 6 Put the clutch back 7T Apply high strength thread locking agent to the threads and install the nut and torque to 40 ft lb 54Nm with the special socket CAUTION Use high strength red thread locker on t

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